Exercisers who wish to develop the chest and neck muscles in particular may wish to do dips, which exercise the chest and back muscles and overhead pull-ups with the arms separated, which exercise especially the back muscles. Traditionally these are performed on fixed parallel bars and fixed overhead bars respectively. These are considered powerful and effective exercises but are very difficult for most people as they involve in their traditional forms, the resistance of the entire bodyweight for which the person may not be strong enough. A further problem with the traditional approach is that the person may sway, swing, contort or leap to cheat the full impact of the exercise.
Apparatus to date has attempted to provide a system for providing variable levels of support to exercisers who cannot pull up with or dip with their entire body weight. For example, U.S. Pat. No. 5,322,489 describes support provided through the exerciser kneeling or standing on a platform which provides upward lift according to the level of weight selected.
Such systems suffer from the defect that the exerciser may vary his position in such a way that the exercise is rendered suboptimal or ineffective in that they may sway or lean in different ways to avoid the target muscles of the exercise being used.
Furthermore as the body is fully extended above the knees, full isolation of the pectorals and latissimus is unlikely to be achieved as with heavier resistance the exerciser will increasingly use his abdominals and erector spinae as accessories.
A further problem with existing art is that where a high weight is used to counterbalance the exerciser's own weight, the foot or knee support may spring up inconveniently when the exerciser attempts to alight.